Rarely are Reps. Michele Bachmann of Minnesota and John A. Boehner of Ohio publicly on the same side of a GOP primary campaign. But a band of geographically and ideologically diverse Republicans are rallying behind Texas Rep. Ralph M. Hall, who is in danger of becoming the first incumbent defeated in 2014 later this month.

Hall's political trouble initially caught many off-guard. Texas House members offered plenty of moral support in the days and weeks after Hall failed to secure the nomination in the March 4 primary. But, according to Hall's recent fundraising reports, including his pre-runoff report filed May 15, his colleagues have backed up that talk over the past couple of months.

Nearly every Republican member of the Texas delegation, including Sen. John Cornyn, has donated to Hall's campaign, which brought in $401,000 from April 1 to May 7, including a $100,000 loan from the candidate. Some members made multiple donations through both their campaigns and leadership PACs.

"Congressman Hall has been a workhorse in Congress, and he stands up for conservative values,” Hall adviser Ed Valentine said of the onslaught of financial support from under the Dome. "He always has. He continues to do that. His type of leadership is sorely needed in Washington.”

Hall is facing a significant challenge from attorney John Ratcliffe in the May 27 runoff for the GOP nomination in Texas' 4th District. As a result, he was recently named one of Roll Call's 10 most vulnerable incumbents .

The 91-year-old, 17-term incumbent was forced into an extended primary campaign after getting off to a sluggish start. But Hall — and his friends in Congress — have pushed hard to financially fortify his final bid for office.

Hall just narrowly missed winning the nomination in the March 4 primary, with Ratcliffe finishing a distant second. Still, a majority of Republican voters in the district Hall has represented since Ronald Reagan's first presidential election cast ballots against the incumbent. That alone put Hall in jeopardy in what's expected to be a smaller runoff turnout.

The first sign that Hall was in trouble came in early January, when Ratcliffe dwarfed the incumbent in fundraising after putting $400,000 of his own money into his insurgent campaign.

But in the campaign's final weeks, Hall now has the financial upper hand. Hall reported $436,000 in cash on hand for the final weeks of the race. Ratcliffe, who raised $143,000 in the pre-runoff period, had $190,000 left in the bank as of May 7.

Thanks to the efforts of Hall's backers in Congress — rallied by Texas Republican Rep. Lamar Smith — the incumbent's haul was a stunning figure, given his previously paltry fundraising. Texas Republican Reps. Joe L. Barton, Blake Farenthold, Kay Granger, Ted Poe and Pete Sessions were among the dozen or so who contributed to Hall's campaign in his pre-primary report. More Texans donated to Hall's campaign in March.

In addition to most of the Lone Star State delegation, contributors included members of House leadership such as Boehner and National Republican Congressional Committee Chairman Greg Walden. In all $215,000 of Hall's $301,000 in contributions came from political action committees and other campaigns.

The financial help from Capitol Hill also ranged from committee chairmen such as Pennsylvania Rep. Bill Shuster to freshmen like New York Rep. Chris Collins and a handful of other rank-and-file members.

"He’s called in all the favors," Ratcliffe consultant Matt Mackowiak said of Hall's fundraising. "We’re not that surprised. We’re encouraged with the support we’ve gotten."

Hall put the money to use in a six-figure TV buy tarring Ratcliffe as a "trial lawyer."

www.youtube.com/watch?v=23kDKn7bmWk

And over the past few weeks, the Hall campaign rolled out national endorsements from Bachmann, former Texas Rep. Ron Paul, former Arkansas Gov. Mike Huckabee and former Speaker Newt Gingrich, all of whom have run for president.

But not everyone is on Team Hall.

Once it became clear Ratcliffe was a serious contender, the Club for Growth and the Senate Conservatives Fund financially backed the insurgent effort. The club bundled nearly $123,000 for Ratcliffe, according to a group spokesman, and spent approximately $23,000 on direct mail, according to Federal Election Commission records.

Most Texas operatives assume the May 27 runoff will be close. Hall has strong name identification, but Ratcliffe organized early and has had a consultant team in place for months. Operatives on the ground say that Hall still has some organizational ground to make up.

"We feel very good with where we are," Mackowiak said.

"He's been around a long time, has a high name ID, thanks to the power of being an incumbent," he added. "But I'd rather be us that them."

Ratcliffe is on the air in his own "six-figure" TV buy, making the argument that it is time to retire Hall.

www.youtube.com/watch?v=ADdLl_4Jj5o

The outcome remains unpredictable. The primary runoff takes place the day after Memorial Day, when Texas schools begin to let out for the summer. Some Republicans on the ground anticipate a disengaged electorate and low turnout. Other operatives expect strong voter engagement, due to a rollicking lieutenant governor's primary race.

Still, the Hall team sounds upbeat about its chances.

“I think the momentum is definitely swinging in our direction," Valentine said. “We’ve seen a groundswell of support within the district since getting into the runoff.”